swiftmailer:
    transport:  smtp
    username:   user
    password:   pass
    host:       example.org
    port:       12345
    encryption: tls
    auth-mode:  login
    timeout:    1000
    source_ip:  127.0.0.1
    logging:    true
    spool:
        type: memory
    delivery_address: single@host.com
    delivery_whitelist:
        - /foo@.*/
        - /.*@bar.com$/
